A study on the antimicrobial resistant patterns and molecular characterization of Staphylococcus aureus isolated from milk

Out of 400 milk samples collected from different sources, 374 samples were positive for Staphylococcus aureus by culture method and confirmed by biochemical tests and 191 isolates (51.07%) were positive by PCR method. All the coagulase positive S. aureus isolates (191) were positive for nuc gene. Out of 191 S. aureus isolates, 15.2% isolates were positive for mecA gene. Among the 374 isolates 191 isolates were confirmed as pathogenic S. aureus by a positive coagulase test. A pannel of 8 antibiotic discs were tested by using the standard disc diffusion method. Among the 191 isolates maximum resistance was observed for penicillin (74.9%) followed by gentamycin (27.2%), erythromycin (21%), cefoxitin (15.2%), and ciprofloxacin (11.5%), tetracycline (7.8%), cotrimoxazole (5.8%), chloramphenicol (0.5%)